Visual servoing involves using visual information to control a system to move from an initial position to a desired position. This may be accomplished by moving an imaging device such that the image produced by the imaging device converges to a predefined desired image. This method requires extraction and tracking of geometric features in the image. Example features include points, lines, image moments, etc. In reality, reliable feature extraction and tracking is difficult. In fact, it is one of the most difficult problems in computer-based vision. Thus, there is a need for direct visual servoing that does not involve extraction and tracking.
Scanning (probe) microscopy has been playing an important role in the research and development of nanotechnology. Nanotechnology refers to the study of matter on an atomic and/or molecular scale. Structures that fall within the realm of nanotechnology generally have one or more dimensions that are between one and one-hundred nanometers.
One type of scanning microscopy is atomic force microscopy (AFM). AFM may also be referred to as scanning force microscopy (SFM). Another type of scanning microscopy that is a predecessor to AFM is scanning tunneling microscopy. Other types of scanning microscopy include, but are not limited to, scanning electron microscopy and transmission electron microscopy.
In AFM, a probe having a tip is suspended at the end of a cantilever. The tip is generally moved (scanned) over the entire surface of a subject. Forces between the tip and the subject cause the tip to move toward or away from the surface of the subject. Based on signals received from the probe by the AFM system, an image of the surface of the subject can be generated and displayed.
The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.